Most protein-based pharmaceuticals contain either no detergent, or relatively mild detergents, such as TWEEN® 80 (polysorbate 80) or TWEEN® 20. However, these mild detergents often are not able to solubilize certain hydrophobic membrane proteins. When hydrophobic membrane proteins are separated from membranes, their exposed hydrophobic regions interact, causing the protein molecules to aggregate and precipitate from aqueous solutions. Such proteins can be solubilized by detergents which have affinity both for hydrophobic groups and for water. Ionic detergents bind to the exposed hydrophobic regions of membrane proteins as well as to the hydrophobic core of water-soluble proteins. Because of their charge, these detergents often denature the protein by disrupting ionic and hydrogen bonds. At high concentrations, for example, sodium dodecylsulfate completely denatures proteins. In contrast, at high concentrations nonionic detergents solubilize biological membranes by forming mixed micelles of detergent, phospholipid, and hydrophobic membrane proteins. However, denatured proteins and proteins in mixed micelles are generally not optimal for use as immunogenic compositions. At low concentrations, these detergents may not solubilize hydrophobic membrane proteins. Zwitterionic detergents have been shown to efficiently solubilize hydrophobic membrane proteins extracted from native membranes and promote refolding of such proteins when produced recombinantly. See Matsuka, Y. V. et al., J. Protein Chemistry 17(7):719-728 (1998). As discussed below, there is a present need for effective immunogenic compositions comprising membrane proteins, for example from the pathogens, N. meningitidis and N. gonorrhoeae. 